在Ubuntu系统中使用crontab，设置定时任务，文件名称test.cron 文件内容：1,30,45,59 echo "run" >~/log.log 测试每分钟将内容run写到文件log.log中，也重启了crontab。
查看定时任务列表：

bdyx1@bdyx1-PowerEdge-R430:~/projects/mongodb_bak$ crontab -l
1,30,45,59 * * * *   echo "run" >~/log.log

bdyx1@bdyx1-PowerEdge-R430:~/projects/mongodb_bak$ service cron status
● cron.service - Regular background program processing daemon
Loaded: loaded (/lib/systemd/system/cron.service; enabled; vendor preset: enabled)
Active: active (running) since 五 2019-09-20 09:56:47 CST; 7min ago

 Docs: man:cron(8)

Main PID: 4639 (cron)
CGroup: /system.slice/cron.service

       └─4639 /usr/sbin/cron -f

9月 20 09:56:47 bdyx1-PowerEdge-R430 systemd[1]: Started Regular background program processing daemon.
9月 20 09:56:48 bdyx1-PowerEdge-R430 cron[4639]: (CRON) INFO (pidfile fd = 3)
9月 20 09:56:48 bdyx1-PowerEdge-R430 cron[4639]: (system) INSECURE MODE (group/other writable) (/etc/crontab)
9月 20 09:56:48 bdyx1-PowerEdge-R430 cron[4639]: (CRON) INFO (Skipping @reboot jobs -- not system startup)
9月 20 09:59:01 bdyx1-PowerEdge-R430 CRON[4666]: pam_unix(cron:session): session opened for user bdyx1 by (uid=0)
9月 20 09:59:01 bdyx1-PowerEdge-R430 CRON[4667]: (bdyx1) CMD (echo "run" >~/log.log)
9月 20 09:59:01 bdyx1-PowerEdge-R430 CRON[4666]: pam_unix(cron:session): session closed for user bdyx1
9月 20 10:01:01 bdyx1-PowerEdge-R430 CRON[4688]: pam_unix(cron:session): session opened for user bdyx1 by (uid=0)
9月 20 10:01:01 bdyx1-PowerEdge-R430 CRON[4689]: (bdyx1) CMD (echo "run" >~/log.log)
9月 20 10:01:01 bdyx1-PowerEdge-R430 CRON[4688]: pam_unix(cron:session): session closed for user bdyx1
bdyx1@bdyx1-PowerEdge-R430:~/projects/mongodb_bak$

但就是在文件log.log文件中看不到内容，是哪里不对吗？